This invention generally relates to a device and method for metering and dispensing precise amounts of particulate matter directly into bins. The invention is particularly applicable for dispensing dry agricultural chemicals, such as pesticides (e.g., herbicides), fertilizers and adjuvants, directly into applicator bins.
Many useful agricultural chemicals and other such products are distributed in dry bulk form, either as powders, granules or small pellets, to the farmers who ultimately use them. Prolonged exposure to high concentrations of many of these chemicals is not recommended, and direct contact should in many cases be avoided.
One useful device for metering and pneumatically transporting agricultural chemicals from a storage bin into applicator bins (e.g., bins on a planter or spreader) is disclosed in U.S. Pat. No. 5,803,673. This device meters precise quantities of particulate matter into a pneumatic air stream which transports the suspended matter through a flexible hose to a portable cyclone separator at which the matter is separated from the air stream and falls out of the bottom of the separator. The major portion of the air stream is recirculated from the separator to the storage bin through a return hose. By holding the separator over an applicator bin, the separated matter tends to fall into the applicator bin. In some instances, dry particulate matter falling from the bottom of the unsealed separator can create airborne dust that, depending on the toxicity of the material, the extent of exposure, and/or size of the dust particles, can create a health hazard.
Because of the potential health hazards associated with exposed chemicals in dry form, some planter manufacturers now provide their planter boxes with tops having self-sealing fill ports. American Cyanamid, for example, markets such a self-closing fill port. When a mating port coupler is attached, the port is opened for filling in such a way that the contents of the box are not exposed to the environment as the coupler is mated to the port. Some other planter boxes have tops with fill ports with simple, sealed covers which, when removed for filling, temporarily expose the box contents to the environment. During filling, air-borne chemical dust may be generated in the planter box by the flow and settling of the chemical, and this dust may vent to the environment before the sealed cover is replaced.
New devices and methods are sought for metering dry chemicals into agricultural applicator bins, such as planter boxes, in ways that avoid either direct contact with the chemicals or significant exposure to air-borne chemical dust. The entire contents of the above-referenced patent are hereby incorporated by reference as if fully set forth.